Well liner



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'Patented Apr. 1s, 1939 UNITED STATES .PATENT OFFICE WELL LINERCalifornia Application July 2.7, 1936, Serial No. 92,800

3 Claims.

This invention relates to the testing and producing of wells and relatesmore particularly to a well liner useful in such operations and to amethod for recovering the same from the well.

A general object of this invention is to provide a practical improvedwell liner and a rapid, inexpensive and commercially practical methodfor handling and recovering the same.

When a well is to be tested or produced it is customary to arrange atubular perforate liner in the open or uncased portion of the well toprevent caving and sanding up of the well. Such liners are usually madeup of a plurality of sections of steel pipe or tubing of standard lengthconnected by right-hand threaded steel couplings. The ow conditions andother conditions in the well often cause the sand and formation totightly pack about the liner. A liner thus sanded in a well is oftenfrozen or immovably caught so that it cannot be removed as a unit.Accordingly, when it is desired to remove a liner from a well to permitdeepening of the well or to carry on other operations it is necessary toresort to costly time consuming fishing operations. Owing to the lengthof the sections of a typical steel liner and to the character of itscouplings it is usually impossible to unthread the sections one from theother in the well and it becomes necessary to cut the liner and removeit from the well in small fragments or parts. As the portions of theliner thus cut free in the Well must be removed one at a time, therecovery of a liner from a Well in the usual manner is a very costly andtime consuming operation.

It is another object of this invention to pro' vide a well liner that isfabricated so that it may be disassembled in the well and recovered fromthe well without resorting to expensive cutting and fishing operations.

Another object of this invention is to provide a well liner soconstructed and formed that its sections may be disconnected in the wellfor individual recovery or for recovery in assemblies of two or moreconnected sections without resorting to cutting, ripping or similarfishing operations.

Another object of this invention is to provide a Well liner fabricatedof a plurality of relatively short sections that may be individuallyrotated and thus successively unthreaded one from the other for recoveryfrom the well under very adverse conditions where the liner is sotightly sanded or caught in the well that it would be impossible tounthread the individual long sections -of a typical liner.

Another object of this invention is to provide a well liner of thecharacter mentioned in which the sections are connected by threadedcouplings formed of a material that is such that the threads will stripor fail in the event that it is found desirable to jar or otherwisemanipulate the liner to free its sections or groups of sections for4removal from the well without unthreading them.

Another object of this invention is to provide a well liner of thecharacter mentioned that is simple and inexpensive and that may bereadily constructed in any desired length.

Another object of this invention is to provide a simple rapid method forrecovering a liner from a Well in unmutlated sections or assemblies ofsections.

Another object of this invention is to provide a method for recovering aliner from a well that effects the separation or disconnection of theliner sections in the Well without resorting to cutting,

ripping, blasting or shooting of the hner.

A further object of this invention is to provide a method for recoveringa liner from a well that is very rapid and does not endanger the well orany of the Well equipment.

The various objects and features of our invention will be fullyunderstood from the following detailed description of a typicalpreferred form of apparatus and manner of carrying out the method of theinvention, throughout which description reference is made to theaccompanying drawing, in which:

Fig. 1 is a longitudinal sectional View of the lower portion of a wellillustrating the liner of the present invention being set therein by asetting tool. Fig. 2 is an enlarged fragmentary longitudinal detailedsectional View taken as indicated by line 2--2 on Fig. l. Fig. 3 is atransverse detailed sectional View taken as indicated by line 33 on Fig.2 and Fig. 4 is an enlarged longitudinal detailed sectional view of aportion of the well illustrating the recovering string and toolextending into the liner.

It is believed that the method of the present bers for lining the openportion of a well. 'I'he sections I may be formed of steel or othersuitable material and are of such diameter that they properly flt theopen portion ofthe well W with the necessary clearance. In practice thelseveral sectionsA I0 may be of the same diameter and may be'of the samelength; It is a feature of the invention that the liner sections I0 arerelatively short being only a few f eet in length. The liner sections I0being relatively short present only limited circumferential surfacesagainst which the sand and caved earth formation may pack and thesections are proportioned so that they may be individually rotated underthe mostradverse caved and sanded up conditions. 'I'his proportioning ofthe liner sections I0 whereby they may be individually rotated when theliner is tightly sanded in the well W is very important as it providesfor the individual disconnection of the sections I0 in the well as willbe subsequently described. It is to be understood that the liner mayembody as many sections I0 as necessary. In other words the liner maylbe constructedof any necessary number of sections I0. 'I'he linersections I0 are perforated to admit the well iiuids. 'Ihe liner may beperforated prior to its introduction to the well or may be perforatedwhen set in the well. In the particular case illustrated in the drawing,the liner sections III are provided with a multiplicity oflongitudinally and circumferentially spaced slots I2 formed thereinprior to the setting of the liner in the well. The slots I2 extendthroughout the portion of the liner which passes through the producingzones of the earth formation. In practice the liner I0 may reston thebottom of the well and its upper end may extend into the lower end ofthe well cas. ing C.

'I'he couplings II are provided to connect the tubular liner sections IIl. In accordance 'with the invention the couplings II are threaded tothe adjacent ends of the sections I0 to releasably or detachably connectthe same. the invention the couplings I I are formed of aluminum or analuminum alloy or other suitable material that has a substantial tensilestrength and yet has a relatively `low shear strength so that threadsout therein will fail or strip under substantial strain. Thus thecollars or couplings II form frangible connections between the adjacent-sections I0 that may be released or broken in the event that thesections cannot be un- -threaded. As illustrated in the drawing theright-hand threads it may be preferred to provide the liner sections Illand the couplings/II with left-hand threads. -This relationship be.-tween the threads of the liner and the threads of the recovering stringfacilitates the disconnection of the liner I0 without endangering thethreads of the fishing string or recovering string.

In arranging or setting the liner of the present invention in the well Wa suitable setting string S may be employed to run the liner through thecasing C. VA releasable connection or setting tool may be provided toconnect the upper end of theA liner with-the setting string S. Thetypical set- In accordance withting tool illustrated in the drawingincludes a tubular adapter I5 threaded on the upper end portion oftheuppermost liner section I0. The adapter I5 has longitudinal slots I6provided with lateral branches I1. Vertical grooves I8 are ,provided onthe interior of the adapter I 5 and extend oupwardly from the slotbranches I1. The setting tool further includes a mandrel I9 threadedlysecured to the lower end of the string S.A The mandrel I9 is adapted toenter the adapter I 5 and has lugs 20 for cooperating with the slots I6.When the liner is to be yrun into the well on the string S the lugs 20are entered in the longitudinal slots I6 and cooperate'with the slots tosecure the liner to the string. Following the proper arranging orsetting of the liner in the well the string S may be manipulated to movethe lugs 20 into the lateral branches II of the slots I6. The lugs 20are moved through the branches l1 into the grooves I8. The string S isthen moved upwardly to withdraw the lugs 20 from the grooves I8 and freethe mandrel I9nfrom the adapter I5. The string S may then be withdrawnfrom the well leaving the liner in the set or operative povsition.

The liner may be set in the manner just described to remain in the wellduring a test of the productivity of the well or during a prolongedphase of the production of the well. The liner serves to admit fluidfrom the producing formations of the well to the lower end of the casingC and the fluids thus prgduced may flow to the surface or may be pumpedfrom the well in the usual manner.

The method of the present invention is intended to facilitate theremoval or recovery of the liner from the well W when it is desired todeepen the well or perform other operations in the well. The improvedmethod of the present invention includes, generally, the engagement ofthe liner with'a recovering string, the application of rotation to theliner from the string for the purpose .of disconnecting the sections I0of the liner, the removal from the well of a section I0 or a group ofsections I 0, thus unthreaded, and if necessary the jarring or other.manipulation of the liner to break the threaded connections at thecouplings II.

In accordance with the method of the invention a recovery string isconnected with the liner for the transmission of force thereto toseparate or disconnect its sections I0. The recovering string employedmay be a string of tubing or pipe connected by threaded couplings. Thethreads of the recovering string are pitched in the opposite directionto the threads on the sections I and couplings II. For example, wherethe threads of the sections I0 and couplings II are lefthand threads, asdescribed above, the threads of the recovering string are right-handthreads. The recovering string is provided with or carries a tool T toengage the liner for the transmission of force from the string to theliner. In practice a releasable overshot adapted for the transmission ofboth longitudinal forces`and rotative forces may be provided on therecovering string to pass downwardly over and engage about the liner. I

The particular tool T illustrated in the drawing is inthe nature-of areleasable rotary spear. Fig` 4 of the drawing illustrates the spear ortool T in its operativeposition within a section In of Vthe liner... Thetool'l? embodies gripping parts or .l slips 22 having teeth for grippingthe interior of the linertc transmit longitudinal force thereto whichteeth are formed or provided with grooves to effectively transmitrotation to the liner. 'I'he spear or tool T is preferably such that itmay be released at the will of the operator. As rotary releasing spearsare well-known to those skilled in the art, the details of the tool Twill be omitted from the present disclosure. The tool T is connectedwith the recovering string to turn therewith and to move longitudinallythereon.

In carrying out the first step of the method the tool T is run into thewell on the recovering string and is entered in the liner. The tool Tmay be run to any desired point within the liner and actuated or set togripits interior. 'I'he tool T may be actuated or set within the upperportion I of the liner and following its .actuation an up- 'iV strainmay be placed on the recovering string in an attempt to bodily lift andrecover the linerv from the well.A If the liner pulls free withoutplacing an excessive o-r hazardous strain on the recovering string itmay be recovered bodily from the well on the string without furtheroperations. However, it may be found that the liner cannot be bodilywithdrawn from the well in this manner in which event the tool T isreleased and is moved to another position in the liner. It may bepreferred to position the tool T a point adjacent but some distanceabove the lower end of the line to apply a turning force to the luier.Following the setting or actuating of the tool T the recovering stringis turned or put under a torque in a direction to unthread the threadsI4 of the liner. In the event that the particular section I0 engaged bythe tool T and the sections I0 above that section are free to turn orare relatively free so that the rotational force applied to the toolturns them, the application of the rotative force may unthread a threadI4 of the coupling I'I justV below the tool T, in which event a portionof the liner comprising several sections I0 may be freed from theremaining sections below the tool T. Following such freeing orunthreading of the assembly of sections I0 the recovering stringcarrying the tool T may be raised to withdraw the freed assembly ofsections I0 from the well, the

tool T serving to connect the assembly of sections with the string. Inthis manner it may be possible to'recover a substantial portion of theline in one operation.

In the event that the above described attempt to unthread a portion ofthe liner fails the tool T may be released and moved to a higherposition in the liner and then re-actuated to grip the interior of theliner. A turning force is then applied to the tool T through the mediumof the recovering string in an attempt to unthread the section I0gripped by the tool T and the higher section I0 from the remainder ofthe liner below the tool T. This second attempt to disconnect the linerIIJ may be successful, in which event the section or assemblies ofsections Ill freed or unthreaded may be recovered from the well asdescribed above. If the second attempt to disconnect the liner fails thetool T may be freed and moved to a higher position and then reset toagain apply an unthreading force to the liner. In this manner the tool Tmay successively set at vertically spaced points to apply unthreadingforce to the liner. In some instances only the upper section I0 orseveral upper sections I0 may be unthreaded from the remainder of the.liner during the rst recovery operation.

The above-described operation of actuating the tool T and applyingunthreading force to the liner to unthread a section i0 or an assemblyof sections III and the recovery of the section or .sections thus freedis repeated until the entire diner is recovered from the well. It may befound that the portion of the liner remaining in the well, following therecovery of one or more sections III, is free to be pulled from the wellin which event the said remaining portion may be bodily recovered withlittle dimculty. It is to be particularly noted that the sections I0comprising the liner are short so that the aggregate locking or holdingforce exerted by the caved formation or sand on one section I0 may bereadily overcome by the turning or unthreading force applied to any onesection by the tool T. Becauseof this proportioning of the sections I0the individual sections I0 or assemblies of sections Ill may besuccessively unthreaded and freed for removal from the well., 'I'heliner I0 may be entirely recovered from the well by merely employing therecovering string and the force applying and lifting tool T withoutendangering the recovering string and without cutting or destroying theliner.

, Under certain circumstances it may be found desirable or necessary tojar the liner or apply longitudinal force'to the liner either before,during or after the above described operations. For example, it may befound that the liner I0 is very tightly sanded in the well throughoutits entire length or a substantial portion of its length, in which caseit may be desirable to attempt to free or partially free the liner tofacilitate the disconnection of its sections I0 in the manner describedabove. Further, it may be found that a certain section I0 or an assemblyof sections I0 is very tightly caught in the well, making it dangerousor impractical to attempt to disconnect it by unthreading.

The method of the present invention provides forthe application oflongitudinal force of the desired intensity and character to theliner tofree it or partially free it and if necessary to release its threadedconnections by brealing the threads thereof. The recovering stringcarries or embodies jars or a jarring tool J. 'I'he jars or tool J maybe located above the force transmitting and lifting tool T. When it isdesired to employ the jarring tool the recovering string is run into thewell to enter the tool T in the selected portion of the liner. The toolT is then set or actuated and the recovering string is manipulated sothat the jarring tool J imparts a jarring action to the liner. Inmostinstances this jarring action will be an upward jarring action forthe purpose of freeing the liner from the well or for shearing orbreaking the threads of the couplings II. Any particular or selectedsection I0 of the liner may be engaged by the tool T for the applicationofthe jarring blows by the jarring tool` J. The recovering string may bemanipulated in a manner to effect the breaking or stripping of thethread or threads I4 of a coupling II to thus free a section IU or agroup of sections I0 thatis caught in the well. 'I'hus the methodprovides for the freeing of a section I0 or a group of sections I 0 thatcould not be freed or disconnected by unthreading it from the remainderof the liner.

It is to be understood .that the jarring tool J I0 engaged by the tool.T maybe more readily i ing force'to a section -IU of the linerto stripthey threads ill ofthe liner Il at the lower end of that particularsection I0.

f 'I'he method ofthe present invention is capable of `eiecting the`recovery of the above-described liner'under practicallyY anycircumstances. The

liner is formed or constructed to be easily lrecovered from the well bythe method of the invention. The method'of the present` inventionprovides for the rapid recovery of a liner from the well withoutendangering any of the equipment and without destroying or mutilatingthe liner.

Having described only a typical preferred form of apparatus and mannerof' carrying out the method of the invention, we do not wish to belimited'or restricted to the specic details herein set forth, but wishto reserve to ourselves any variations or modifications that may appearto4 those skilled inthe art or fall within the sco of the followingclaims:

Having described our invention, we claim:

1. A well liner comprising a plurality of tubular liner sections.threaded at the ends, and couplings threadedly connecting the linersections and formed of a metal considerably weaker than that of theliner sections, each coupling constituting the sole means connectingadjacent liner sections whereby upon application of excessive strains toa liner section to remove it `from the well failure will occur at thecoupling, thus detaching the liner section completely lfrom theremainder of the liner sections and permitting its removal.

2. A well liner comprising a plurality of tubular sections formed ofsteel, threaded at the ends, and an aluminum coupling for joining thesections end to end, said coupling having threads 'at each end formating with the threads on the sections and adapted to rupture under astrain applied to the liner.

3. A well liner comprising a plurality of tubular sections threaded atthe ends, formed of a material such as steel, and threaded tubular meansformed of an aluminous material threadedly connecting adjacent tubularliner sections whereby the connections will rupture upon being subjectedto an abnormal tensional or torsional strain.

ELWIN B. HALL. ARTHUR L. ARMENIROUT.

